Hygrostat



' Feb. 12, 1935.

Y. NORWOOD 1,991,059

HYGROSTAT Filed July 20, 1932 Sheets-Sheet 2 INVENTORV Harry yfNaru ood 1 .9 p 5 US).

4 ATTORNEY Patented Feb. 12, 1935 PATENT OFFlCE HYGROSTAT Harry Y. Norwood, Rush,

Instrument Companies, poration of New York N. Y., assignor to Taylor. Rochester, N. Y., a cor- Application July 20, 1932, Serial No. 623,577

Claims.

This invention relates to devices employed in regulating humidity and more particularly. to hygrostats and relays therefor.

The present invention has for its purpose the 5 provision of a hygrostat and a relay cooperating therewith, which are simple in construction, which are relatively inexpensive to manufacture and which are reliable in operation.

For a clearer understanding of the invention, reference is made to the drawings wherein Fig. 1 represents a plan view of an instrument sensitive to moisture conditions, together with a diagrammatic showing of a fluid pressure operated relay which, in turn, regulates a fluid pressure operated valve to control the admission of moisture into the atmosphere to which the instrument is exposed; Fig. 2 is a cross-sectional detail view of a nozzle suitable for use in the system of Fig. 1; Fig. 3 is a plan view of a fluid pressure relay suitable for use in the mentioned system; Fig. 4 is a side elevation of said relay with portions thereof broken away to illustrate a portion .of the internal construction thereof; Fig. 5 is a vertical sectional view taken substantially on the line 5-5 of Fig. 3; Fig. 6 shows a modified form of a humidity responsive device with its conduit connections which can be substituted for that portion of Fig. 1 included within the dotted rectangle; Fig. '7 is a bottom view of a portion of the structure shown in Fig. 6; Fig. 8 illustrates a modified form of valve structure for use in a reverse acting relay; and Fig. 9 illustrates a diaphragm structure for use in a balanced or modulated re-- lay.

, The present invention is particularly adapted for use in an air conditioning system wherein moisture is supplied through a pipe 1 into a compartment or room (not shown) in which the moisture content is to be regulated, The amount of moisture admitted through pipe 1 is regulated by a well-known type of fluid pressure operated valve 2.. This valve is actuated by fluid pressure supplied to its actuating top through the conduit 3 from the air or fluid pressure supply pipe 4 under the control of air relay valve 5, the structure of which will be hereinafter set forth. The operation of this air relay 5 is controlled by a hunudity-responsive device generally designated 6. This device includes a base '7, at one end of which there is pivotally mounted at 8 a baflle'arm 9 in operative relation to an opening 10 in the nozzle 11, also mounted on the base, which baflle arm. is provided with two extensions 12 and 13, one at each side of the pivot 8. The spiral spring 14 which has one end fastened to the base and the other end fastened to the extension 12, normally tends to move the baflle arm 9 away from the opening in the nozzle, while the moisture responsive element 15 hooked on the extension 13 by hook 13a tends to move the baflle against the action of spring 14. This element may be formed of various hygroscopic materials such as goldbeaters skin, silk thread and the like, but for purposes of this disclosure strands of human hair have been shown. Thestrands 15 at one end 10 may be attached to the loop 13a in any well-known manner and the other end thereof is similarly attached to a loop 16. The loop 16 is carried by a hook 17, adjustably mounted on the short arm of lever 18 which is pivoted at 19 and which has 15 its long arm engaged at one side by the set screw 20 and its opposite surface by the spiral spring 21. A graduated wheel 22 mounted on the set screw may be employed to indicate the amount of the adjustment thereof.

It will be understood that when the hygroscopic element absorbs moisture it will increase its length, thereby permitting the spiral spring 14 to move the bafiie 9 away from the opening 10 in the nozzle. Similarly when the hygroscopic element 15 gives up moisture as the atmosphere to which it is exposed becomes drier, it contracts and operating against the force of the spiral spring 14 moves the baflie 9 toward the opening 10 in the nozzle, in this way regulating the flow of pressure-fluid such as compressed air through the nozzle.

The relay 5, as best shown in Figs. 3, 4 and 5 includes a base 23 provided with threaded nipples 24, 25 and 26 together with a separable cup or cover member 27. The space within the relay is divided into two chambers by the diaphragm structure including the large main diaphragm 28 anda second or auxiliary diaphragm 29 of smaller area, carried by the rigid annular diaphragm mounting plate 30. The diaphragm structure has its periphery. clamped by rubber gaskets such as 31 between the edge of the base and the edge of the cover member 2'7. Screws, such as 32, serve to clamp the cover and base together. At the center of the main diaphragm 28 there is mounted a diaphragm spacer 38 in the form of a sleeve which receives one end of the diaphragm extension 34 centrally attached to the lower side of the auxiliary diaphragm 29. In the cover there is formed an internally threaded valve housing 36 which is closed by the valve housing cap 37. Within the housing there is mounted a screwthreaded valve body 38 provided with an opening therethrough to be closed by a valve seat 40. A

valve stem 39 provided with the valve seat 40 has an extension which engages the end of the dia* phragm extension 35 centrally mounted on the auxiliary diaphragm opposite the extension 34. A spring 80 surrounding the valve stem and engaging both the cap 37 and a portion of the valve seat 40 tends to maintain this valve in engagement with the valve body. The opening in the nipple 24 communicates through a hollow dowel pin 40, with a duct 41 formed within the walls of the cover. This duct communicates through the opening 42 in the sleeve with the space at the top of the valve 40, so that when it opens, compressed air is supplied therethrough to the chamber at the upper side of the auxiliary diaphragm 29. The opening in nipple 26 communicates with the chamber at the underside of the main diaphragm 28 so that the diaphragm structure will assume a position determined by the fluid pressure admitted through the nipples 24 and 26. The nipple 25, as best shown in Fig. 24 communicates through the hollow dowel 43 and the duct 44 with the air chamber at the upper side of the auxiliary diaphragm 29.

In the operation of this system, compressed air or other pressure fluid from a suitable source is supplied through the conduit 4 and the branch conduit 40., nozzle structure 11, conduit 4b to the chamber below the main diaphragm 28, thereby building up pressure therein depending on the amount of leakage through the opening 10 in the nozzle 11 as determined by the position of the bafile 9. It will be remembered that the position of this bafile is dependent on the condition of the strands 15 which are responsive to changes in humidity. Similarly fluid pressure from the conduit 4 passes through the branch 40, duct 41, opening 42, and if valve seat 40 is in its open position, thence to the chamber at the upper side of the auxiliary diaphragm 29. As pressure builds up in the space above this diaphragm, it passes through duct 44, conduit 3, to the actuating top of the motor valve 2 causing itto open. For example, if the humidity to which the element 15 is exposed becomes greater, this element expands and permits the spring 14 to move the baffie 9 away from the opening in the nozzle 10. This allows increased leakage of air through the opening 10 in the nozzle 10 so that the pressure in the chamber at the lower side of the diaphragm 28 decreases until the diaphragm 28 resumes the position shown in Fig. 5, wherein it permits the valve seat 40 to close under the action of the spring 80. When the valve seat 40 closes, it prevents the admission of compressed air through the branch 40 and duct 41 into the chamber'at the upper side of the diaphragm 29. Consequently air in this chamber as well as in the pipe 3 and the actuating top of the motor valve 2, gradually leaks away through the adjustable leak 50 until the motor valve 2 is moved to its normal or closed position wherein moisture is prevented from passing through the pipe 1 into the chamber where the moisture conditions are being regulated.

However, if the amount of moisture in the chamber decreases, the element 15 contracts thereby moving'the bafile 9 into engagement with the opening 10 in the nozzle 11. The closure of the opening 10 in the nozzle 11 permits pressure to build up in the chamber on the lower side of the diaphragm 28, thereby elevating this diaphragm which movement through the action of the diaphragm spacer 33 and extension 35, opens valve seat 40 so that pressure fluid may flow through the duct 41 and thence through this valve into the chamberat the upper side of the auxiliary diaphragm 29. Fluid from this chamber passes out through the pipe 3 to the actuating top of the motor valve 2. This motor valve is thus opened to permit the passage of moisture into the chamber. It will be understood that since the diaphragms 28 and-29 are of unequal area, it is possible to obtain a throttling action of the motor valve 2 to any posiiton between its opened and closed positions just described. In this manner a very accurate control of humidity conditions in a compartment can be obtained.

In Fig. 6 a modified form of moisture-responsive unit is shown within the dotted rectangle, which may be substituted for the corresponding equipment shown within the dotted rectangle of Fig. 1. In this unit there is provided a mounting plate 51 on the upper side of which there is provided a hollow tube 52 preferably of foraminous sheet material. The upper end of this tube is closed by a removable cap 53 provided at its center with an aperture to receive a hook 54. This hook supports a loop 55 to which one end of the hygroscopic element 56 is attached. The lower end of this element is fastened to a loop 57 which is engaged by a link 58 hooked on to the extension 59 of the baffle 60. This bafile is pivoted at 61 on the arm 62 which, in turn, is pivotally mounted at 63 on a bracket 64 of the base. The arm 62 at its free end is apertured to receive a screw 65 which is screwed into the threaded shoulder attached to the base. A spring 67 surrounding the screw 65 affords a slightly resilient mounting for the pivoted arm 62. spring 68 fastened at one end to the base and at its other end to an extension 69 of the baflie, tends to move the baflie against the nozzle 11 which is mounted on the inside of the base 51. This nozzle has an opening 10 communicating with the conduit branch 4a. The action-of the hygroscopic unit just described is the same as that disclosed in Fig. 1, but it affords a convenient arrangement for a vertical mounting of the hygroscopic unit, whereas that shown in Fig. 1 is best adapted for horizontal mounting.

The relay illustrated in Figs. 3, 4 and is of the direct-acting type but it can be converted into a reverse-acting relay by substituting the housing cap 37a, valve body 38a and valve seat 40a for the corresponding elements in Fig. 5. In this instance the duct 41 communicates with an opening 81 in the cap 37a so that air pressure flows to the top of the valve. In this arrangement air pressure under, diaphragm 28 maintains the valve seat 40a in its closed position, whereas in the direct-acting relay air pressure under this diaphragm maintains the valve opened.

In Fig. 9 there is shown a single diaphragm 28b which may be substituted for the diaphragm structure including the diaphragms 28 and 29 of Fig. 5, when it is desired to change the relays previously disclosed into one of the balanced or modulated type.

The present disclosure is merely for purposes of illustration and is not to be taken in a limiting sense, since there may be many modifications and variations thereof within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In a pressure fluid operated device, a base having three openings therein, a cover for said base, a diaphragm structure mounted in fluid tight relation between the base and the cover to form two chambers therein, one of the openings in said base communicating with the chainberat one side of said diaphragm structure, the second opening in said base being connected to said second chamber through a duct formedwithin the walls of the base and cover, valve mechanism having an opening communicating with said second chamber, and means for connecting said third opening in the base to said second chamber through said valve.

2. In a pressure fluid operated relay, a base having three openings therein, a cover for said base, a diaphragm structure mounted in fluid tight relation between the base and the cover to form two chambers, one of the openings in said base communicating with the chamber at one side of said diaphragm structure, means within the base and cover for connecting the second opening in said base to said second chamber, valve mechanism having an opening communicating with said second chamber and means within the base and cover for connecting said third opening in the base to said second .chamber through said valve. I

3. In a pressure-fluid operated device, a base having three openings therein, a cover for said base, said cover having an opening thereinsurrounded by an' internally threaded valve housing, a threaded valve body screwed into said housing, a valve cooperating with said body, a cap for said housing, 9- diaphragm structure mounted in fluid-tight relation between the base and the cover to form two chambers therein, one of the openings in said base communicating with the chamber at one side of said diaphragm structure, the second opening in said base being connected to said second chamber through a duct formed within the walls or the base and cover, and means for connecting said third opening in the base to said second said valve. a g

4. In a pressure-fluid operated device, a base having three openings therein, a cover for said base, said cover having an opening therein surrounded by an internally threaded valve housing, a threaded valve body screwed into said housing, and a diaphragm structure mountedin fluid-tight relation between the base and the cover to form two chambers therein, one of the openings in said base communicating with the chamber at one side of said diaphragm structure, the second opening in said base being connected to said second chamber 'through a duct formed within the walls of the base and cover, and said third opening in the base being connected'to the interior of said valve body through a duct formed within the walls of the base and cover.

5. In a pressurefluid operated device, a base having three nipples refining openings therein, said nipples lying in'a common plane and radiating from a common center, a cover for said base, a diaphragm structure mounted in fluidtight relation between the base and the cover to form two chambers therein, one of the openings in said base communicating, with the chamberat one side of said diaphragm structure, the second opening insaid base being connected to said second chamber through a duct formed chamber through within the'walls of the base and cover, valve "HARRY Y. NORWOOD. 

